design: extract document-as-is UI contract (DESIGN.md + DTCG tokens)

Case-B extract of the as-built dark UI into design/: 9-section DESIGN.md,
W3C DTCG tokens.tokens.json, brand/palette.css + assets, and inspiration/
provenance (incl. the rendered red-shade decision). Two owner calls layered
in: red elevated to the single brand accent (#DC2626), two-tier radius
(4px controls / 8px containers). AGENTS.md gains the read-before-UI Design
line + design/ in the layout tree; ROADMAP gains the design-checker cleanup
backlog. No UI code changed.

ROADMAP.md

@@ -36,6 +36,20 @@ Done in 1.1.0:9 (P2 batch): input-validation 500s → 400 (`lib/http.ts readJson
 - CSV export↔import round-trip: export writes `setX`-prefixed headers (`setCalories`/`setWatts`/`setNotes`) the importer doesn't read (it expects `calories`/`watts`/`notes`), so the app's own CSV export silently drops those on re-import (calories long-standing; watts since 1.2.0:4). Fix by aligning export header names with the parser, or adding the prefixed names as `knownColumns` aliases. (JSON account export/import round-trips fine.)
 - Charts/progress views over history (the data and 1RM estimates already exist).
 
+## Design
+
+Cleanup backlog from the 2026-06-19 design-contract extract (`design/DESIGN.md` + `tokens.tokens.json`). The contract documents the *intended* system; these are the spots where the code diverges. All cosmetic/mechanical — none ship-blocking. Found by the `design-checker` agent (re-run it for fresh file:line lists).
+
+- **Unify off-palette neutrals → zinc** (21 hits, 12 files): every `hover:bg-gray-100`/`active:bg-gray-200`/`hover:text-gray-200` on the white primary button → `zinc-200`/`zinc-300`. Canonical hover is `zinc-200` (`color.action.primary-hover-bg`). Worst: `app/main/workouts/page.tsx` (4), auth `LoginForm`/`SignupForm`, `dashboard/page.tsx`, `programs/page.tsx`.
+- **Unify success hue → emerald** (10 hits): `green-*` → `emerald-*`. Worst: `components/settings/SettingsForm.tsx` (6), `WorkoutForm.tsx:696`, `SetRow.tsx:477`, `ExerciseCard.tsx:12`.
+- **Unify warning hue → amber** (13 hits): `yellow-*` → `amber-*`. Worst: `app/main/import/page-csv.tsx` (6), `SettingsForm.tsx` (6), `ExerciseCard.tsx:14`.
+- **No solid red button** (1): `components/settings/DangerZone.tsx:101` uses `bg-red-700` — convert to the ghost/wash destructive treatment (`text-red-400 border-red-800 hover:bg-red-950/30`). (Red elsewhere — 65 wash/outline/text uses — already conforms.)
+- **Radius two-tier (4px control / 8px container)**: `rounded-md` (6px, 27 hits, mostly `SetRow.tsx` ×16 + `WorkoutForm.tsx` ×9) → `rounded`; `rounded-lg` on primary *buttons* (5 hits in `workouts/page.tsx`, `dashboard/page.tsx`) → `rounded`. (`rounded-full` on the FAB is fine.)
+- **Shadows are overlay-only**: drop `shadow-2xl` on the static login/signup cards (`app/auth/{login,signup}/page.tsx:23`) and `shadow-lg` on the FAB + desktop CTA (`workouts/page.tsx:163,174`) — depth = bg layering + border.
+- **Sub-scale font sizes** (10 hits): `text-[10px]`/`text-[11px]` (below the 12px `text-xs` floor) → `text-xs`.
+- **Extract a shared `<Button>`** (`components/common/` is empty): the white primary pattern is inlined 44× across 21 files — the structural reason the `gray-100` drift spread everywhere. A single component is the durable fix and the single point to enforce the contract. (Biggest item; do after the mechanical sweeps.)
+- **Token wiring decision**: `design/brand/palette.css` (`--pow-*` vars) isn't imported anywhere. For a Tailwind app the class names already *are* the tokens (hexes match the zinc/emerald/amber ramp), so the pragmatic path is to keep using Tailwind names and treat `palette.css`/`tokens.tokens.json` as the canonical cross-reference (and for any raw-CSS context). Alternatively import `palette.css` at the root and migrate the ~30 inlined `bg-[#0A0A0A]` canvas hexes to `var(--pow-bg-canvas)`. Decide before doing a hex→var sweep.
+
 ## Hygiene
 
 - Delete the legacy `start9/0.4/workout-log_x86_64.s9pk` build artifact; drop unused `bcryptjs` from `start9/0.4/package.json`.